Substance use among high-school students in Southern Thailand: trends over 3 years (2002-2004).

PURPOSE To examine the trends of substance use and correlated variables in high-school students in Southern Thailand. METHODS Surveys of high-school years 7, 9 and 11 and vocational school year 2 students in four provinces in Southern Thailand were conducted in 2002-2004 to examine lifetime substance use, use within 1 year and 30 days before the interview, using a self-completed questionnaire. RESULTS The prevalence of lifetime use of any illicit substance was 5-7% overall (about 7%, 9% and 13% in boys and 2%, 1% and 3% in girls in 2002, 2003 and 2004, respectively). Krathom, a local addictive plant, and cannabis were the most commonly used illicit substances on a lifetime basis with prevalences of 2.3%, 2.8%, 4.9% (p<0.01) and 2.6%, 2.3%, 3.4% (p>0.05) in the surveyed years. The rates of alcohol consumption in the past 30 days were 19.3%, 17.3% and 15.2% (p>0.05) while smoking rates were 14.6%, 8.8% and 10.8% (p<0.05). The significant correlates of current illicit substance use were surveyed year, male, vocational school, school level, and school performance. CONCLUSION The problem of substance abuse is increasing among Thai adolescents. School-based interventions seem desirable, especially in boys, vocational and public school students.